1. The Diversity of Prokaryotic Organisms
Chapter 11

2. Domains Bacteria and Archaea
One circular chromosome
not in a membrane
70S ribosomes
No membrane-bound organelles
Binary fission
rRNA provides evidence of phylogenic differences between the 2 Domains

3. Domain Bacteria Proteobacteria
Includes most of the gram-negative bacteria
Phylogeny based on rRNA studies
Common photosynthetic ancestor
few are still photosynthetic
Mythical Greek god, Proteus
Largest taxonomic group of bacteria
Classes designated by Greek letters

4. The  (alpha) Proteobacteria
Some grow at low nutrient levels
Some have unusual morphology
Many are agriculturally important
several medically important genra

5. The  (alpha) Proteobacteria
Human pathogens:
Bartonella - bacillus
Cat-scratch disease

6. Obligate intracellular parasite:
Rickettsia – bacillus or coccobacilli
Arthropod-borne cause spotted fevers
R. typhi - Endemic murine typhus (fleas)
R. rickettsii - Rocky Mountain Spotted Fever (ticks)

7. Have prosthecae: Caulobacter Hyphomicrobium
Stalked bacteria found in low nutrient aquatic environment
Hyphomicrobium
Budding bacteria found in low nutrient environment

8. Pelagibacter Very small with tiny genome
P. ubique is abundant marine microbe

9. Nitrogen-fixing bacteria: Azospirillum
Grows in association with tropical grasses and sugar cane
Rhizobia
Rhizobium, Bradyrhizobium
Infects roots of legumes forming root nodules

10. Nitrifying bacteria : Chemoautotrophs Oxidize nitrogen
Nitrosomonas NH4+  NO2– (ammonium to nitrite)
Nitrobacter NO2–  NO3– (nitrite to nitrate)

11. Plant pathogen: Agrobacterium
Inserts plasmid into plant cells, inducing tumors
Crown gall

12. Produce acetic acid from ethyl alcohol:
Acetobacter
Gluconobacter

13. Wolbachia Most common infectious bacteria
Endosymbionts of insects and other animals

14. The  (beta) Proteobacteria
Utilize nutrients diffusing from areas of decomposition of organic matter
hydrogen gas, ammonia, and methane

15. Thiobacillus Sphaerotilus Chemoautotroph, oxidizes sulfur: H2S  SO42–
- hollow sheath
- polar flagella
- problem in sewage

16. Spirillum
Large, aerobic freshwater bacterium

17. Neisseria
N. meningitidis
Meningococcal meningitis
N. gonorrhoeae

18. Bordetella B. pertussis - whooping cough
Aerobic, rods or coccobacillus
B. pertussis - whooping cough

19. The  (gamma) Proteobacteria
Largest subgroup
Great variety of physiological types
Includes the enterics

20. Azotobacter and Azomonas
Beggiatoa
Chemoautotroph, oxidize H2S to S0
Gliding motility
Beggiatoa alba is only species
Azotobacter and Azomonas
Nitrogen fixing, free-living soil bacteria
Large ovoid cell with heavy capsule

21. Francisella Francisella tularensis – tularemia (rabbit fever)
Pleomorphic
Francisella tularensis – tularemia (rabbit fever)
Resistant to many antibiotics

22. Pseudomonas Aerobic rods; Polar flagella
Extra-cellular and/or florescent pigments
Opportunistic pathogen
Metabolize wide variety of substrates
Resistant to many anti-microbials
Denitrification

23. Legionella L. pneumophilia
Found in streams, warm-water pipes, cooling towers
L. pneumophilia
Causes a form of pneumonia called legionellosis
Survive inside aquatic amoeba

24. Coxiella Coxiella burnetii Q fever Obligate intracellular pathogen
transmitted via aerosols or milk
Resistant spore–like body

25. Vibrio Vibrio cholerae V. parahaemolyticus
Facultative anaerobic vibrio
Vibrio cholerae
Cholera
Dysentery
V. parahaemolyticus
Less severe gastroenteritis
Undercooked shellfish

26. Pasteurella P. multocidia - carried by Komodo dragon
mainly pathogens of domestic animals
Cause pneumonia and septicemia
passed to humans from cat and dog bites
P. multocidia - carried by Komodo dragon

27. Haemophilus H. ducreyi H. influenzae
inhabit mucous membranes of upper respiratory tract, mouth, vagina, and intestinal tract
require heme fraction (X factor) and NAD cofactor (V factor)
H. ducreyi
Chancroid (STD)
H. influenzae
meningitis, pneumonia, bronchitis, septic arthritis, earaches

28. Enterobacteriales (enterics):
Facultatively anaerobic, rods
Peritrichous flagella
Most ferment glucose and other sugars
Inhabit intestinal tract of animals (humans)

29. Enterics Escherichia Salmonella S. enterica – 2400 servors
Coliforms – fecal contamination
UTI and Travelers Diarrhea
Food poisoning – E. coli 0157:H7
Salmonella
S. enterica – 2400 servors
S. enterica servor typhi – typhoid fever

30. Enterics Shigella Klebsiella K. pneumoniae – serious form of pneumonia
Shigellosis (bacillary dysentery)
Klebsiella
K. pneumoniae – serious form of pneumonia
Some species fix nitrogen

31. Enterics Yersinia Proteus Y. pestis – plague Swarmer cells
UTI and wound infections

32. The  (delta) Proteobacteria
Some species are predators on other bacteria
Important contributors to the sulfur cycle

33. Bdellovibrio Aerobic, rod with polar flagella
attack other gram (-) bacteria similar to the way a virus would

34. Desulfovibrio Human intestinal tract and anaerobic sediments
obligate anaerobe, sulfur reducing bacteria
Use S for final electron acceptor
Release tons of H2S annually

35. Myxococcus Gliding motility Feed on bacteria they encounter
Cells aggregate to form fruiting body loaded with myxospores

36. The  (epsilon) Proteobacteria
Microaerophilic, helical or vibrioid rods
Motile by means of flagella

37. Campylobacter Helicobacter C. fetus C. jejuni H. pylori
causes spontaneous abortion in domestic animals
C. jejuni
leading cause of bacterial diarrhea
Helicobacter
H. pylori
common cause of stomach ulcers